West Ham maintained their 100% record for 2012 and elevated themselves to the top of the Championship, at least until Monday, and condemned their rudderless visitors to an 18th league defeat of the season.

Two Mark Noble penalties, both awarded for handball, were enough to dispatch Nottingham Forest who once again showed that they could float like a butterfly but were swatted away by the industrial force of West Ham. Lewis McGugan conjured a rare goal for Forest – they had scored only once in nine games – with a stunning strike from deep, but it came too late to make West Ham fret.

"It wasn't our best of days but when you can dig one out when you aren't on form shows the resilience and the commitment of the players," said Sam Allardyce. "We're top of the league and while we didn't do it the way we wanted to do it, we did it all the same."

Forest remain on a downward curve, their plight exacerbated by results elsewhere, and have garnered only 16 points out of a possible 51 under Steve Cotterill. The former Portsmouth manager described Forest's performance against Southampton as "disgraceful" and against Leeds "appalling". In the 4-0 FA Cup defeat by Leicester City the players were "going through the motions", but Cotterill detected an upturn in form in this defeat, where wasted chances cost his side dearly.

"We've been poor but this was much better. We could have been two or 3-0 up before they gave the penalties. The first wasn't a penalty and the second didn't deviate. The ball must have hit the hairs on [Chris Gunter's] arm," he said.

"You need to take your chances but you can't just tap a player on the shoulder and make them a 20-goal a season striker. We've just got to get through this year."

Under normal circumstances Cotterill would have been sacked, but due to the club's £76m debts they would have to have accepted a £500,000 bid for the defender Wes Morgan, tabled by Leicester this week, to pay their manager off.

Forest's plight can be put into perspective by a glance at West Ham's squad – where Carlton Cole, Frédéric Piquionne, John Carew and the promising Sam Baldock often vie for one striking berth.

A lack of punch at home has encouraged the club to consider a bid for Rangers' Croatia forward Nikica Jelavic. The Ibrox club's manager, Ally McCoist denied that West Ham had offered £6m for the 26-year-old, who is also believed to have been tracked by Fulham and Liverpool. "They've not made an official bid. £6m is not nearly enough," said McCoist. Jelavic is believed to have been offered to West Ham, who according to Allardyce, have "made an enquiry and there has been talks but I don't know if there has been a bid. That's not my department."

All the same West Ham should be encouraged by the news that James Tomkins, the coveted 22-year-old defender, signed an improved contract that will keep him at the club until 2016.

Forest started this game in a surprisingly confident fashion, although Marcus Tudgay undid one crisp passage of play by firing wildly over when unmarked and well set while the gifted but flighty McGugan wasted another decent chance.West Ham looked strangely discordant, rarely clicking into gear in a disjointed first half. One chance went begging when Jack Collison left Julien Faubert's cross for Mark Noble and the midfielder fired wide. Collison then forced a good save from the Forest goalkeeper Lee Camp after an excellent headed pass from Papa Bouba Diop, who minutes later limped off with a hamstring injury.

If that setback ratcheted up the tension around Upton Park it was soon dispelled, when the referee Steve Bates awarded a penalty after a handball from Guy Moussi and Noble thumped home from the spot. "Quite a fortunate penalty to be awarded," said Allardyce.

Forest were at least easy on the eye, and they twice came close to equalising in the 56th minute, when Gunter completed a one-two before firing straight at Robert Green and then the substitute Dexter Blackstock had his first touch swept off the line.

Their fragility was soon exposed, however, when Collison careered through the defence to shoot over for West Ham, Lansbury forced another save from Camp and then, as chaos spread, Gunter misjudged a loose ball and handled in his own area. Noble, more delicate this time, sent Camp the wrong way.